Mycotic pseudoaneurysm of the aortic isthmus secondary to salmonella infection causing a diagnostic dilemma

Mycotic Pseudoaneurysm: Clinical Course, Management and Prognosis

Pseudoaneurysm of vessels (most common in arteries), in general, happens when a blood vessel wall is damaged leading to leakage of blood and its collection in the surrounding tissue, essentially resulting in a false aneurysm. These false collections can be problematic and can develop in any location. However, their most common clinical presentation is in the femoral arteries. These manifest especially following an endovascular intervention. Here, we discuss a case of a 73-year-old male whose in-hospital course was complicated by the development and subsequent infection of a pseudoaneurysm after he was admitted for sepsis from a UTI. We further highlight the pathophysiology related to the formation of a pseudoaneurysm, and the mechanism of action behind various treatment modalities used. The clinical course and possible treatment options may vary. However, a robust combination of early surgical management alongside medical management seems to provide the best outcome.

Mycotic Pseudoaneurysm Formation at the Cannulation Site in the Ascending Aorta

The formation of mycotic pseudoaneurysms in the ascending aorta is a rare but sometimes fatal complication after open-heart surgery, requiring cardiopulmonary bypass (CPB). There has been little cited about this rare complication. We present a case of a 51-year-old man who developed a mycotic pseudoaneurysm in the ascending aorta at a previous aortic cannulation site nine years after coronary artery bypass surgery. The patient presented to the emergency department with two weeks of worsening substernal chest pain and was found to have pseudoaneurysm in the anterior wall of the ascending aorta on chest computed tomography angiography (CTA) during his chest pain workup. The patient's blood cultures grew methicillin-susceptible Staphylococcus aureus (MSSA). During the hospital course, the patient's respiratory status worsened, and repeat CTA revealed enlargement of the pseudoaneurysm arising from the anterior proximal arch of the aorta. Chest X-ray obtained because of hypoxia demonstrated widening of the upper mediastinum, which appeared increased compared with the previous exam. Because of concern for rupture of an aneurysm, the patient was taken to the operating room for redo sternotomy and repair of the pseudoaneurysm with femoral artery cannulation for cardiopulmonary bypass. The patient completed eight weeks of IV nafcillin, and rifampin was added to decrease biofilm formation.

Ruptured pseudoaneurysm of the thoracic aorta mimicking lung cancer: A case report

A 70‐year‐old woman was admitted to a local hospital with a five‐day history of back pain. She had been referred to our hospital after an abnormal chest shadow was identified on chest X‐ray. Chest computed tomography (CT) revealed an anterior mediastinal mass in the upper lobe of the left lung. Her general condition was good. She was diagnosed with lung cancer, and examination was planned. However, respiratory failure rapidly worsened on hospital day 2, and a ruptured pseudoaneurysm of the thoracic aorta (PTA) was diagnosed from contrast‐enhanced CT. Emergency thoracic endovascular aortic repair was successfully performed, and her postoperative course was uneventful. The hemodynamics of the PTA were stable in the case of this patient, but the risk of rupture is extremely high and frequently fatal. PTA should therefore be included among the differential diagnoses of mediastinal tumor.

Key points

Significant findings of the study

Pseudoaneurysm of the thoracic aorta (PTA) may present on imaging findings that resemble lung cancer.

What this study adds

PTA should be included among the differential diagnoses of mediastinal tumor. Clinicians therefore need to be familiar with the imaging findings of PTA.

Mycotic (Infected) Pseudoaneurysm, a Diagnostic Challenge - Case Series

Mycotic pseudoaneurysm (or infected pseudoaneurysm) is an infectious arteritis, leading to the destruction of the arterial wall with the formation of a blind, saccular outpouching contiguous with the arterial lumen. Delayed management or non-management of mycotic pseudoaneurysms is associated with high morbidity and mortality due to complications such as arterial rupture, hemorrhage, and fulminant sepsis. Earlier diagnosis of mycotic pseudoaneurysm is essential for time management. Multidetector computed tomography (MDCT) is a widely used imaging modality for detecting the mycotic pseudoaneurysm, its characterization, and vascular mapping. MDCT findings of mycotic pseudoaneurysm are blind, saccular outpouching of an artery with irregular arterial wall, perivascular soft-tissue mass, or edema. Uncommon results of MDCT include arterial lumen thrombosis, arterial wall calcification, and perivascular gas. Management of mycotic pseudoaneurysm includes endovascular stenting with graft repair, endovascular embolization, open surgery, medical therapy (intravenous antibiotics), or a combination of these. We report three cases of mycotic pseudoaneurysm affecting aortic isthmus, a segmental branch of the pulmonary artery, and the internal mammary artery. All cases posed a diagnostic challenge, which only on subsequent imaging revealed to be a mycotic pseudoaneurysm.